A glitch is an undesired digital pulse that usually has a short duration. Glitches may be a result of a design problem in digital circuits such as application specific integrated circuits (ASICs). Such glitches may cause faults in the operation of digital systems. For example, a design problem may result in a glitch in a signal coming out of an ASIC. Another digital circuit may receive the signal with the glitch as an input. The glitch may be interpreted by the second digital circuit as a legitimate pulse and as a consequence, the second circuit may not function correctly.
Glitches are many times a result of improper design of digital circuits that receive asynchronous inputs. Such glitches typically occur immediately following a legitimate change in the signal, either following a falling edge or following a rising edge of that signal.
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